Apparatus and method for treating slurries

ABSTRACT

An apparatus for treating slurries, in particular biogenic or industrial slurries, can include at least one treatment rotor which is arranged or can be arranged in the slurry and which rotates or is rotatable about an axis of rotation (R), with treatment elements which project outward, as seen from the axis of rotation (R), and between which interspaces are formed, at least some of the treatment elements having, at—at least one, preferably each—adjacent interspace, in each case at least one treatment edge, preferably at least two treatment edges spaced apart from one another, each of these treatment edges running from the inside outward, as seen from the axis of rotation. Methods for treating slurries are also disclosed, including methods using the apparatus for treating slurries.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.13/715,373, filed Dec. 14, 2012, which is a Continuation ofPCT/EP2011/059620, filed on Jun. 9, 2011, which claims priority toGerman Patent Application Number DE 10 2010 023 793.0, filed Jun. 15,2010. The entire content of each of the aforementioned patentapplications is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus and a method in each case fortreating slurries, particularly of industrial or biogenic origin.

2. Background and Relevant Art

Such apparatuses and methods are used for the treatment or evenrenovation of slurries, particularly of slurries of industrial origin,slurries from mining operations, sedimentary slurries in bodies of waterand/or biogenic slurries.

Biogenic slurries of animal or human origin are usually mixtures of aliquid phase or liquid, mostly mainly water, and a solid phase or solidparticles. The solid phase in this case usually comprises biogenicparticles or organic solids, cells and microorganisms, in particularbacteria, and aggregates of these. In addition, biogenic slurries maycomprise organic or inorganic substances and also a gas phase, forexample in the form of gas bubbles or dissolved gas. The gas may comefrom the aerobic or anaerobic decomposition of organic material.Biogenic slurries from waste water purification are also designatedsewage slurries.

In sewage plants, the waste water or dirty water to be purified usuallycomes, after mechanical prepurification, into a detritus pit in whichundissolved substances, such as faecal substances and paper, etc.,settle or float on the surface. Pretreated dirty water is then usuallysubjected to a biological clarifying stage. In this case, organicsubstances are decomposed, in particular, aerobically by microorganismsand inorganic substances are partially oxidized. Customary methods forthis biological stage are activated sludge methods with subsequentsecondary clarification. In the activated sludge method, biogeniccontents of the waste water or dirty water are continuously decomposed,with the supply of air, biotically by oxidation and aerobically by theaddition of activated sludge which contains bacteria aggregated, forexample, in flaky form. During secondary clarification, the activatedsludge settles and is thus separated from the waste water. Part of thesludge can be recirculated as what is known as return sludge into theactivated sludge method in order to keep the concentration ofmicroorganisms sufficiently high. The excess sludge which has occurreddue to the growth of biomass during secondary clarification isthickened, for further treatment, together with the primary sludge frompreclarification and is then decomposed further anaerobically, forexample, in digestion towers. Digested sludge resulting from this, afterpassing through a secondary thickener, is delivered to a sludge pressfor dewatering and, after being dewatered, can be disposed of.Clarification methods may also be carried out without preclarification.In this case, only the excess sludge from secondary clarification isdelivered to the sludge press via a prethickener, usually without adigestion tower.

For the dewatering of slurries, in particular sewage or industrialslurries or sedimentary slurries, it is known to separate the slurryliquid fraction, composed essentially of water, by means of a filterplant or centrifuge, solid constituents simultaneously being separatedfrom the slurry. Furthermore, dewatering with bags or hoses made from(geo)textile filter materials is also known.

A flocculent (a flocking aid) which contains polymers is usually mixedwith the slurry before dewatering, in order to increase the degree ofdewatering or degree of drying of the slurry, that is to say to dewaterthe slurry more effectively. The way in which the flocculent acts may beimagined as being that the polymers bind the solid particles in theslurry to one another in flakes or so as to form flakes and therebyassist or improve their separation from the water. The dewatered drymass filtered out is also designated as a filter cake. The polymers alsoimprove the passage of water through the filter cake in the case of thesubsequent slurry quantities.

DE 198 08 156 A1 discloses an apparatus for the treatment ofconditioning agent (flocculent) for aqueous slurry, with a rotatingdistributor head for mixing a mixture of active substance parentsolution and additional water in a mixing chamber and with aninoculating device which dispenses the active substance solution mixedin the mixing chamber, as conditioning agent, to the aqueous slurryflowing in a feed pipe. The distributor head has, distributed about itsaxis of rotation, essentially two longitudinal slots running parallel tothe axis of rotation, as fluid outlets for the mixture, and also twomixing blades extending radially outward and along the axis of rotationand designed as strips. The longitudinal slots are arranged in thecircumferential direction between the mixing blades. The mixture flowsthrough a shank of the distributor head and through the slot shapedfluid outlets outward into the mixing chamber and is fully mixed thereby the two mixing blades. The mixing blades have on their outercircumference or region located radially furthest outward, in a firstembodiment, mixing-in edges running parallel to the axis of rotation andend edges adjoining these axially at the front and rear and runninginward in a curved manner or, in a second embodiment, circular mixing-inedges running in a longitudinal plane containing the axis of rotation.The mixing in edges of the mixing blades swirl and mix the flocculent,introduced via the slots, in the slurry. The rotational speed of thedistributor head is set in a range of between 700 rev/min (revolutionsper minute) and 2500 rev/min.

The effectiveness of the biological purification stage in sewage plantscan be increased in that homogenizers or else disintegrators are usedfor treating the sewage sludge, in particular the return sludge, primarysludge or excess sludge and also digested sludge.

By means of such disintegrators, the size of the solid particlescontained in the sludge can be reduced and homogenized, with the resultthat a larger effective surface for decomposition becomes available.Furthermore, by disintegration, enzymes adhering to cell walls andbiogenic particles can be detached and thus introduced into the liquidphase. Further, in disintegration, cell walls of cells and the like canbe at least partially broken up, with the result that endoenzymes of thecells are released. In particular, the disintegration actions mentionedincrease the efficiency of biological decomposition by microorganisms inthe sludge, in particular in the activated sludge of the biologicaldecomposition stage.

A disintegration rotor for sewage sludges is known, for example, from DE37 19 441 A1. The known disintegration rotor has twisted blades with acurved front. Rotation of the disintegration rotor in the sludge resultsin disintegrating cavitation effects.

A disintegration rotor having external blades for sewage sludges isknown from JP-2002 248493. When this disintegration rotor rotates,disintegration is brought about by cavitation between the blades.

U.S. Pat. No. 6,402,065 B1 discloses a disintegration rotor with bladesarranged parallel to the axis of rotation, in which rotor the sludgeflows radially.

DE 20 2005 000 875 U1 discloses a disintegration rotor in which thesludge is routed radially from the inside outward through partiallynozzle like cavities.

Disintegration of sludges can admittedly be achieved by means of theknown disintegration rotors. However, the achievable disintegrationaction is still worth improving.

BRIEF SUMMARY OF THE INVENTION

On the basis of this, in particular, an object of the invention is toprovide a novel apparatus and a novel method in each case for treating,in particular mixing in conditioning agent and/or disintegrating,slurries.

This object is achieved by means of the features of patent claim 1.Refinements and developments according to the invention may be gatheredfrom the dependent claims.

The apparatus according to patent claim 1 is suitable and intended forthe treatment of slurries, particularly of biogenic or industrialorigin, and comprises at least one treatment rotor which is arranged orcan be arranged in the slurry and which rotates or is rotatable about anaxis of rotation running generally through, preferably centrallythrough, the treatment rotor, and treatment elements which projectoutward, as seen from the axis of rotation, and between whichinterspaces are formed, at least some of the treatment elements having,at at least one, preferably each, adjacent interspace, in each case atleast one treatment edge, preferably at least two treatment edges spacedapart from one another, each of these treatment edges running from theinside outward, as seen from the axis of rotation. The run of thetreatment edges is, in particular, such that the spacing of the pointson the treatment edge from the axis of rotation increases along the runor extent of the treatment edge continuously, preferably strictlymonotonically. In particular, the run of the treatment edges is radialor linear, but may also be curved or else linear and oblique withrespect to the radial direction.

In an advantageous embodiment, the treatment of the slurry is a mixingof conditioning agent, in particular flocculent, into the slurry, thetreatment rotor then being designed as a mixing in rotor and thetreatment elements of the treatment rotor being designed as mixing inelements and each treatment edge being designed as a mixing in edge.

In a further advantageous embodiment, the treatment of the slurry isdisintegration of the slurry, the treatment rotor being designed as adisintegration rotor and the treatment elements of the treatment rotorbeing designed as disintegration elements and each treatment edge beingdesigned as a disintegration edge.

The embodiments for mixing in conditioning agent and for disintegrationmay also be combined with one another, in particular in two stagesystems or in successive processes.

The invention is based on the idea of providing on a treatment rotor aplurality of treatment elements (or treatment teeth, treatment tenons)which protrude (or project) outward away from the axis of rotation ofthe treatment rotor or transversely to the axis of rotation and whichare separated or spaced apart from one another by interspaces (or gaps),and which, furthermore, have, toward the adjoining or adjacentinterspace or adjoining or adjacent interspaces in each case at leasttwo treatment edges running outward in a direction away from the axis ofrotation and spaced apart from one another.

This bundle of measures according to the invention synergisticallyimproves the treatment action, in particular mixing in action ordisintegration action, of the treatment rotor and increases theintroducible treatment energy, in particular mixing energy ordecomposition energy for the disintegration of constituents of theslurry, in particular cellular aggregates or cells.

In particular, by the meandering or introduction of spaced aparttreatment elements, the effective edge length of the (active) treatmentedges is increased and the latter, as swirling edges, considerablyincrease the mixing of the flocculent in the slurry or thedisintegration of the slurry. The interspaces between the treatmentelements lead the slurry/conditioning agent mixture or the slurry pastthe treatment edges during the rotation of the rotor, so that thetreatment edges can also act virtually over their entire length upon themixture or the slurry and introduce treatment energy. Moreover, therotational speed of the rotor can be reduced because of its higherefficiency and therefore, in general, electrical drive energy can besaved.

In the case of a flocculent as conditioning agent, the mixing energyintroduced is in direct correlation to the binding energy duringflocculation/flake-formation, so that flocculation can therefore also beimproved as a result of measures according to the invention.

Consequently, according to the invention, an entirely novel generationof mixing apparatuses for mixing conditioning agents, in particularflocculants, into slurries is provided, which, because of the enormousincreases in efficiency and the energy saving consequently achieved,will technologically supersede the mixing apparatuses existing hitherto.The invention therefore constitutes a technological and economic quantumleap in the sector of flocculation and mixing in technology. A similarstatement can be made with regard to application for the disintegrationof slurries. The slurries may be any slurries, in particular sewagesludges or industrial slurries.

In advantageous variants according to the invention, the treatmentelements or, alternatively or additionally, the interspaces between thetreatment elements have a special shape with regard to their crosssections.

The width, measured in the direction parallel to the axis of rotation,of at least some of the treatment elements increases at least partiallyin the direction of rotation and/or the internal dimension or width,measured in the direction parallel to the axis of rotation, of at leastsome of the interspaces between the treatment elements decreases atleast partially in the direction of rotation. What is achieved therebyis a compression of the slurry/conditioning agent mixture or of theslurry which improves the treatment action as a result of the pressuredifferences and, where appropriate, cavitation effects which occur.

This increase in the width of the treatment elements or the decrease inthe width of the interspaces may be continuous or monotonic or evenstrictly monotonic in the direction of rotation, so that increasingcompression can take place. The inlet orifice of the interspaces is thenusually larger than the outlet orifice.

In an especially advantageous embodiment, however, the width, measuredin the direction parallel to the axis of rotation, of at least some ofthe treatment elements, in this embodiment, first decreases in thedirection of rotation (or direction of circulation, circumferentialdirection) and only then increases again, preferably in such a way thatthe treatment elements have a concavely curved, preferably biconcavelycurved configuration. Alternatively or additionally, the internaldimension, measured in the direction parallel to the axis of rotation,of at least some of the interspaces between the treatment elements firstincreases in the direction of rotation and then decreases again,preferably in such a way that the interspaces are in each case ofconvexly curved, preferably biconvexly curved form. The variation in thewidth or internal dimension in the direction of rotation or ofcirculation is preferably continuous, but, for example, the situation isnot ruled out where the width or internal dimension is partiallyconstant.

This variation in the width of the treatment elements or in the internaldimension of the interspaces results, at the treatment elements or inthe interspaces between adjacent treatment elements, in an additionaldecompression and subsequent compression of the slurry/conditioningagent mixture or of the slurry. On the one hand, because of thesepressure and flow conditions the flow routing of the slurry/conditioningagent mixture or of the slurry in the interspaces is improved and thismixture or slurry is also swirled at the interspace, at a secondtreatment edge located behind a front treatment edge in the direction ofrotation, and is therefore acted upon successively with mixing energy atat least two treatment edges. On account of this forced flow through theinterspace as a result of the geometry of the latter, this gives rise toan additional treatment effect with a further increased introduction ofmixing energy. On the other hand, the decompression and subsequentcompression of the slurry/conditioning agent mixture lead to additionaltreatment effects as a result of the pressure differences, amounting tocavitation effects. In this embodiment, the selected configuration andsize of the inlet orifice of the interspaces may be the same as those ofthe outlet orifice, but may also be different.

The selected ratio of a maximum width to a minimum width of thetreatment elements is preferably greater than 2, preferably between 2and 3.5. The selected ratio of a maximum width to a minimum width of theinterspaces is preferably greater than 1.4, preferably between 1.5 and2.8.

Preferably, the conditioning agent is introduced into the slurry betweentwo treatment elements succeeding one another in the direction ofrotation, particularly in that the conditioning agent is delivered froma rotor inner space outward through perforations or orifices in therotor which lie between the treatment elements. However, theconditioning agent may also, alternatively or additionally, beintroduced into the interspaces directly through outlet orifices in therotor which are arranged between the treatment elements provided to therespective interspace and which issue directly into the interspaces.

The treatment rotor proves to be especially effective when, during itsrotation about the axis of rotation, it dips completely into the slurryor is surrounded by this.

The treatment edges are preferably arranged at or in marginal regions ofthe interspaces which form inlet orifices or outlet orifices of theinterspaces for the mixture of slurry and conditioning agent. Since theflow cross sections of the interspaces are additionally smallest atthese marginal regions, the flow velocity is highest there and thereforeswirling at the treatment edges is also optimized.

In an especially advantageous embodiment, two treatment edges of twodifferent treatment elements adjacent to the same interspace lieopposite one another, with the result that the mixture is swirled andacted upon with mixing energy especially strongly between the two mixingin edges acting virtually simultaneously or jointly.

Preferably, two front treatment edges at the inlet orifice of theinterspace lie opposite one another and two rear treatment edges at theoutlet orifice of the interspace lie opposite one another. As a result,in each case two treatment edges can act directly from both sides orjointly upon the mixture at the narrowest locations, specifically firstduring the inlet of the latter into the interspace and then during itsoutlet from the interspace.

These measures lead to further improved treatment efficiency.

In a special structural refinement, at least two treatment edges of atreatment element are connected by means of a flat side, in particulartwo treatment edges are connected by means of a first flat side and twofurther treatment edges by means of a further second flat sidepreferably parallel to the first flat side. Furthermore, preferably,treatment edges lying opposite one another are connected to one anotheron the two flat sides via concavely curved side walls which form lateralboundary walls of the interspaces. The side walls are preferablydesigned to be mirror symmetrical with respect to at least one plane ofsymmetry, preferably with respect to a plane of symmetry lying in themiddle between the two flat sides and parallel to these and/or withrespect to a plane of symmetry lying in the middle between two treatmentedges and orthogonal to the flat sides.

Furthermore, a (radially external) outer face, connecting the end pointsof the treatment edges, of the treatment element may be designed as aflat side and/or an inner (radially internal) boundary wall of theinterspace may be designed as a flat side. The length of the treatmentelements or of the treatment edges is generally greater than the clearwidth of the interspaces, in particular preferably at least 1.5 times to3 times greater.

In general, the treatment rotor has a rotor basic body on which thetreatment elements are fastened or integrally formed. The rotor basicbody is preferably internally hollow with an inner space which isenclosed by a preferably essentially hollow cylindrical wall.

Preferably, at least one perforation in the wall is provided, via whichthe inner space of the rotor basic body is flow connected to the outsidespace, so that conditioning agent flowing in or through the inner spaceis introducible or can be introduced through the at least oneperforation into the slurry located in the outside space. At least oneperforation may be designed as an axial slot running essentiallyparallel to the axis of rotation.

It is especially advantageous if the perforation or perforations is orare arranged between treatment elements, as seen in the direction ofrotation, and/or in each case at least one perforation is arranged ineach case between two treatment elements, as seen in the direction ofrotation. The perforations are preferably arranged so as to be offset toone another in the direction of rotation, preferably distributedequidistantly, in particular so as to be offset in pairs to one anotherby about 180° and/or offset in each case by about 90° to the treatmentelements preferably offset by 180°.

The treatment rotor has in general a coupling element which adjoins therotor basic body axially with respect to the axis of rotation and viawhich the treatment rotor can be coupled to a preferably varied speed orvariable speed rotary drive, in particular a rotary shaft of the rotarydrive, for the purpose of rotating the treatment rotor about the axis ofrotation.

According to an advantageous refinement, a plurality of treatmentelements of the treatment rotor are arranged so as to be offset in adirection parallel to the axis of rotation, in particular in at leastone row, preferably in at least two rows, preferably the or each rowrunning parallel to the axis of rotation or else helically about theaxis of rotation. Furthermore, preferably, at least two treatmentelements are arranged on a circle about the axis of rotation or in thesame axial position along the axis of rotation and are offset to oneanother by a spacing angle, preferably these at least two treatmentelements being arranged in a paired rotationally symmetrical arrangementor at identical spacing angles to one another and/or the rows ofpluralities of treatment elements being arranged at equal spacing anglesto one another or with rotational speed symmetry.

Furthermore, in general, at least some, preferably all, of the treatmentelements are spaced apart from one another on the outside facing awayfrom the axis of rotation and/or the interspaces between these treatmentelements are designed to be outwardly open on their outside facing awayfrom the axis of rotation. In such a version, the interspaces can bekept free of blockages more easily, without appreciable decreases inefficiency having to be accepted.

Alternatively, however, at least some of the treatment elements, inparticular the treatment elements in each case in a row or line, mayalso be connected to one another, on the outside facing away from theaxis of rotation, by means of an outer region of the treatment rotor,and/or the interspaces between these treatment elements may be closedoff on their outside facing away from the axis of rotation.

To avoid unbalances in the treatment rotor, it is advantageous if thetreatment rotor, in particular its treatment elements, are arranged anddesigned in such a way that the mass center of gravity of the rotor lieson the axis of rotation or the axis of rotation is a main axis ofinertia (characteristic axis) of the rotor. For example, in each casethe same number of treatment elements may be arranged on opposite sidesor lines of the treatment rotor. This also includes arranging thetreatment elements in a paired rotationally symmetrical, mirrorsymmetrical or point symmetrical arrangement.

A further embodiment of the invention relates to an apparatus fortreating slurry, in particular biogenic slurry, which comprises at leastone treatment apparatus according to the invention and comprises atleast one liquid extraction device following or subsequent in thedirection of flow of the slurry, in particular dewatering device, inparticular filter press or centrifuge, or textile dewatering hoses orbags, for the purpose of reducing the liquid content, in particularwater content, of the slurry.

The axis of rotation of the treatment rotor is preferably directedtransversely, preferably perpendicularly, to the direction of transportof the slurry which is routed, in particular, through a transport line.

A further aspect of the invention relates to a method for mixingconditioning agent, in particular flocculent, into a slurry, anapparatus as claimed in one of the preceding claims being used, and thetreatment rotor being surrounded essentially completely, but at leastwith its treatment elements, by the slurry or being arranged or dippedin the slurry.

The conditioning agent, in particular flocculent, added to the slurrypreferably promotes or intensifies the separation of the liquid phase orliquid, in particular water, from solids, including solid fractions ofcells of organic origin contained in the slurry, of the slurry. Inparticular, flaky structures of different size are formed from solidparticles and/or solid cellular constituents of the slurry andflocculent and liquid, in particular water, is released from the slurry.

A further aspect of the invention relates to a method for thedisintegration of slurries, an apparatus according to the inventionbeing used and the treatment rotor being surrounded essentiallycompletely, but at least with its treatment elements, by the slurry orbeing arranged or dipped in the slurry and being rotated about its axisof rotation.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are described in more detailbelow by means of figures in which:

FIG. 1 shows a perspective illustration of a treatment rotor,

FIG. 2 shows a cross section of the treatment rotor of FIG. 1 along asectional plane directed perpendicularly to the axis of rotation,

FIG. 3 shows two treatment elements with an interspace in longitudinalsection,

FIG. 4 shows a side view of the treatment rotor according to FIG. 1,

FIG. 5 shows a top view of the treatment rotor according to FIG. 1,

FIG. 6 shows a further embodiment of a treatment rotor in a side view,

FIG. 7 shows a perspective view of an apparatus for mixing aconditioning agent, in particular flocculent, into a slurry, and

FIG. 8 shows a side view of the apparatus according to FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIGS. 1 to 8, identical or functionally identical elements aredesignated by the same reference symbols. The refinements described inconnection with the figures (fig.) are described only in as much as isnecessary for understanding the invention. Furthermore, the figures arenot necessarily true to scale and scales may vary between the figures.

FIGS. 1 to 5 show a first exemplary embodiment of a treatment rotor 1and parts of it, and FIG. 6 shows a second exemplary embodiment of atreatment rotor.

FIGS. 7 and 8 show an apparatus 7 for treating slurry S, in particularbiogenic slurry (or, if appropriate, also a mixture of slurry S andflocculent F), in particular for mixing in flocculent F or for thedisintegration of slurry S. The treatment rotor 1 is mounted rotatablyin a T shaped portion of an only partially illustrated transport or feedline 9 for the slurry S. The treatment rotor 1 projects into theinterior of the feed line 9.

The treatment rotor 1 has an internally hollow rotor basic body 2 withan inner space 20, which is enclosed by an essentially hollowcylindrical wall 21, and a plurality of treatment elements 4 and 14fastened or integrally formed on the rotor basic body 2 and projectingor protruding outward, in particular in a direction radial to the axisof rotation R.

The treatment rotor 1 is rotatable about an axis of rotation R runningcentrally through the treatment rotor 1 and for this purpose has acoupling element (connecting shaft) 3 which adjoins the rotor basic body2 axially with respect to the axis of rotation R and via which thetreatment rotor 1 can be connected or coupled to a rotary drive (10 inFIGS. 6 and 7), not illustrated in FIG. 1, for the purpose of rotatingthe treatment rotor 1 about the axis of rotation R. The direction ofrotation of the rotary movement of the treatment rotor 1 is designatedby T and, in general, is a direction tangential to a circle about theaxis of rotation R or a direction running along a circle about the axisof rotation R and continuously following the circle curvature. In theexample of FIG. 1, the direction of rotation T selected is clockwise,but may also be directed oppositely or counterclockwise or even bechanged regularly to prevent clogging of the treatment rotor 1.

The treatment elements 4 and 14 are designed, in particular, astreatment tenons or treatment teeth. In the exemplary embodimentillustrated, the treatment rotor 1 has, on opposite sides, so as to beoffset by about 180°, two rectilinear rows, running parallel to the axisof rotation R, of in each case, for example, five treatment elements 4on one side and 14 on the other side, which are configured essentiallyidentically to one another.

For mixing conditioning agent, in particular flocculent F, into a slurryS, the treatment rotor 1 is designed as a mixing in rotor and itstreatment elements as mixing in elements and their treatment edges asmixing in edges. Such an application is preferably described here.

For the disintegration of a slurry S (or, if appropriate, of a mixtureof slurry S and flocculent F), the treatment rotor 1 is designed as adisintegration rotor and its treatment elements are designed asdisintegration elements and their treatment edges as disintegrationedges.

In each case perforations 6 are provided in the wall 21 between thetreatment elements 4, on the one hand, and the treatment elements 14, onthe other hand, as seen in the circumferential direction or direction ofrotation T, and, as can be seen in FIGS. 1, 2 and 5, are designed asaxial slots running parallel to the axis of rotation R, but may also beconfigured or arranged differently or be varied in number. Theperforations 6 are likewise offset to one another by about 180° and tothe treatment elements 4 and 14 in each case by about 90°. The innerspace 20 of the rotor basic body 2 is flow connected to the outsidespace by means of the perforations 6.

In FIG. 6, additional outlet orifices 55 are provided in the boundarywalls 50 between the treatment elements 4 and 14, as seen axially, issuedirectly into the interspaces 5 and 15 and likewise connect the innerspace 20 of the rotor basic body 2 to the outside space.

The treatment elements 4 are spaced apart or separated from one anotherby interspaces 5 and the treatment elements 14 by interspaces 15.However, more than two such rows of spaced apart treatment elements mayalso be provided.

The treatment elements 4 and 14 all project outward essentially radiallyto the axis of rotation R and have in each case four preferablyrectilinear treatment edges 41, 42, 43 and 44 which run outward parallelto a radial direction, perpendicular to the axis of rotation R,essentially perpendicularly to the direction of rotation T and parallelto one another and which have essentially the same length L4.

As can best be seen in FIG. 3, in each case two treatment edges 41 and42 of a treatment element 4 and 43 and 44 of an adjacent treatmentelement are adjacent to the interspace 5 lying between them, andpreferably two opposite treatment edges 41 and 43 of the adjacenttreatment elements 4 lie at an inlet orifice 51 of the interspace 5 andtwo opposite treatment edges 42 and 44 of the adjacent treatmentelements 4 lie at an outlet orifice 52 of the interspace 5. Thus, thetwo treatment edges 41 and 42, adjacent to the interspace 5, of onetreatment element 4 are spaced apart from one another and the treatmentedges 43 and 44 of the other treatment element 4 are likewise spacedapart from one another by the amount of the spacing between the inletorifice 51 and outlet orifice 52 or the dimension L1, measured in thedirection of rotation T, of the interspace 5. The same also appliescorrespondingly to the treatment elements 14 and the interspaces 15.

As illustrated, the inlet orifice 51 and the outlet orifice 52 may be ofequal size or have an equally large (flow) cross-sectional area,preferably even the same configuration, but may also be different.

The two treatment edges 41 and 43 are connected by means of a flat side47 of the treatment element 4 and 14, while a further flat side 48,parallel to the flat side 47, of the treatment element 4 and 14 liesbetween the treatment edges 42 and 44.

By contrast, the opposite treatment edges 41 and 42 and also 43 and 44on the two flat sides 47 and 48 are connected to one another viaconcavely, that is to say inwardly, curved side walls 45 and 46 whichtherefore also form the lateral boundary walls of the interspaces 5 and15, which boundary walls are therefore curved convexly, that is to sayoutwardly, from the point of view of the interspaces 5 and 15. Theconfiguration of the side walls 45 and 46 is in each case, inparticular, mirror symmetrical with respect to a plane of symmetry lyingin the middle between the two flat sides 47 and 48 and parallel tothese, for example cylindrical. Furthermore, preferably, the two sidewalls 45 and 46 are also mirror symmetrical to one another with respectto a plane of symmetry located in the middle between the two treatmentedges 41 and 43 and orthogonal to the flat sides 47 and 48.

Consequently, in more general terms, the axial width, measured parallelto the axis of rotation R or perpendicularly to the direction ofrotation T, of the treatment elements 4 and 14 decreases from a maximumwidth L2 at the front on the flat side 47 first inward, as far as themiddle of the treatment element 4 or 14, to a minimum width and thenincreases again at the rear on the flat side 48 to a maximum width L2.Complementarily to this, the axial width, measured parallel to the axisof rotation R or in the direction of rotation T, of the interspaces 5and 15 increases from a minimum width L3 at the front first inward, asfar as the middle of the interspace 5 or 15, to a maximum width and thendecreases again rearward on the outside to a minimum width L3. This canbe seen especially clearly in FIG. 3, where, for example, a greaterwidth B1 of the treatment element 4 with an associated smaller width W1of the interspace 5 and a smaller width B2 of the treatment element 4further inward with an associated greater width W2 of the interspace 5are illustrated. This (more general) teaching for the configuration ofthe treatment elements or interspaces can also be implemented by otherversions, apart from those illustrated in FIGS. 1 to 5, for example byanother configuration of their cross sections with differently curvedand/or even asymmetric side walls 45 and 46 and other axial widths. Forexample, only one side wall 45 or 46 may also be concave and the otherplanar or even convex.

The outer face, connecting the end points of the treatment edges 41 to44, of the treatment elements 4 and 14 is designated by 49 and ispreferably designed as a flat side. The inner boundary walls of theinterspaces 5 and 15 are designated by 50 and are preferably likewise offlat form.

On the end face in front of the row of treatment elements 4 or 14,further outwardly projecting treatment elements 7 and 17 configuredidentically to one another are in each case arranged so as to be spacedfrom the adjacent first treatment element 4 or 14, but are curvedrearward on the end face so that the treatment rotor 1 can more easilybe fitted transversely into a pipe cross section of the flow pipe forthe slurry S. By its shape being sloped or curved at the front, thetreatment rotor 1 can be adapted to the curved inner walls of thetubular transport or feed line 9 and can be introduced as far aspossible into the feed line 9 transversely to the longitudinal directionof the latter, that is to say to the direction of transport of theslurry S, without the treatment elements butting against the inner wallsor touching these during the rotation of the treatment rotor 1.

Further shapes suitable for this purpose may also be envisaged for thetreatment elements or the treatment rotor 1. For example, the radiallength L4 of the treatment elements 4 and 14 may also vary according tothe respective shape of the feed line. Furthermore, it is not necessary,as in the present exemplary embodiment, for the treatment elements 4 and14 to have essentially the same shape.

At the rear ends of the two rows of treatment elements 4 and 14 thereis, in each case spaced apart from the adjacent last treatment element 4and 14, a fastening element 8 or 18 for the fastening of the treatmentrotor 1 to a corotating part of a floating ring seal, not illustrated.

The depth of the interspaces 5 and 15 corresponds to the length L4 ofthe treatment edges 41 to 44. The interspace between a fastening element8 or 18 and a treatment element 4 or 14 is less deep, with the depth L8,for stability reasons.

The treatment elements 4 and 14 and also 7 and 17 preferably lie inpairs at the same axial positions along the axis of rotation R, as dothe fastening elements 8 and 18. This is achieved, in particular, in anembodiment in which the treatment rotor 1 has symmetry with respect torotation through 180°. In an embodiment with three or four or, ingeneral, n rows of treatment elements, instead of only two, thisrotational speed symmetry must then be in terms of 120° or 90° or, ingeneral, 360°/n.

The overall length of the two lateral rows of treatment elements 17 and4 or 7 and 14, on the one hand, and the fastening element 8 or 18 isdesignated by L6. The outside diameter of the treatment rotor 1 betweenthe outsides of the two rows, corresponding to the outer faces 49 of thetreatment elements 4 and 14, is designated by L5. The diameter of thebasic body 2, that is to say its (maximum) dimension perpendicularly tothe axis of rotation R, is designated by L7.

The dimensions L1 to L7 may, without any restriction in generality, beselected as follows: L1 between 6 mm and 28 mm, L2 between 3 mm and 17mm, L3 between 2 mm and 14 mm, L4 between 12 mm and 220 mm, L5 between80 mm and 510 mm, L6 between 88 mm and 530 mm and L7 between 21 mm and270 mm.

The functioning of the treatment rotor 1 may be described as follows:

During the rotation of the treatment rotor 1, for mixing flocculent Finto a slurry S, a flocculent F routed or flowing through the innerspace 20 is introduced, as can best be seen in FIG. 2, through theperforations 6 essentially radially away from the axis of rotation Routward into the slurry S located in the outside space. The mix ormixture of slurry S and flocculent F is designated by S+F.

The flocculent F serves in a way known per se and already describedabove for conditioning the slurry S, in particular for improving theefficiency of a subsequent mechanical liquid extraction, in particulardewatering, in particular by means of a press or centrifuge or awater-permeable textile bag or the like.

The flocculent F introduced into the slurry S via the perforations 6 isthen mixed into the slurry S further and with a higher degree oftreatment by the in each case next and, if appropriate, followingtreatment element or treatment elements 4 or 14, while at the same timetreatment energy is introduced.

In this case, during the rotation of the treatment rotor 1 in the slurryS, the slurry/flocculent mixture S+F is pressed or routed in a flowdirection opposite to the direction of rotation T through theinterspaces 5 between the treatment elements 4 (or interspaces 15between the treatment elements 14), as can be seen clearly in FIG. 3.The mixture S+F passes through the inlet orifice 51, which lies betweenthe treatment edges 41 and 43, at the front in the direction of rotationT, of the adjacent treatment elements 4, into the interspace 5 and thesame current flows past these front treatment edges 41 and 43. The fronttreatment edges 41 and 43 work or act as swirling and stalling edges forthe flow of slurry/flocculent mixture S+F. The mixture, however, is notpressed or thrown outward on account of the centrifugal forces, butinstead, in the case of the treatment rotor 1 according to theinvention, necessarily remains initially on the treatment rotor 1.

To emphasize, the mixture S+F of slurry S and flocculent F is pressed orrouted through the interspace 5 and flows out of the interspace 5 againonly at the outlet orifice 52. As a result, the mixture S+F also flowsin forced flow past the second pair of opposite treatment edges 42 and44 at the outlet orifice 52 and is acted upon anew with mixing energy bythese and swirled.

As compared with the prior art, therefore, according to a first effectof the invention, the number of active treatment edges or treatmentedges acting upon the same volume fraction of slurry/flocculent mixtureS+F is increased by four, to be precise the four treatment edges 41 to44, adjacent to the interspace 5 (or 15), of the adjacent treatmentelements 4 (or 14).

As compared with a treatment rotor having a treatment edge which isaxially continuous on the outside, an active edge length of thetreatment edges or swirling edges of 4 L4 per interspace 5 or 15 and 4L8 in the case of the last two interspaces is obtained. During thetreatment rotor 1 illustrated, therefore, the overall edge length willbe 40 L4+8 L8. For example with L4=20 mm and L8=16 mm, a swirling edgelength of 928 mm is therefore obtained.

This increased number or length of treatment edges according to theinvention results in a considerable improvement in the treatment resultor in the introduction of mixing energy.

A second effect which brings about an improved treatment result arisesfrom the variation in the flow cross section of the interspace 5 (or 15)for the mixture S+F flowing through. Since the cross section of theinterspace 5 (or 15) initially increases in the flow direction, themixture S+F is first decompressed, that is to say the static pressure isreduced on account of the higher dynamic pressure, and is subsequentlycompressed since the cross section of the interspace 5 (or 15)thereafter decreases again. If the inlet orifice 51 and outlet orifice52 have essentially the same flow cross section, the static pressuresupon the inlet and upon the outlet of the mixture S+F into and out ofthe interspace 5 (or 15) are also essentially identical.

As a result of this decompression and subsequent compression of theslurry/flocculent mixture S+F, as compared with conventional treatmentrotors additional mixing in effects arise which lead to improved mixingof the flocculent F into the slurry S.

On the one hand, initially in conjunction with the first effect due tothe pressure profile inside the interspaces 5 (15), the mixture S+F issucked properly into the interspaces 5 (15) and does not deviate outwardeven before the rear treatment edges 42 and 44, but instead also flowsalmost completely over the rear treatment edges 42 and 44 upon outletfrom the interspaces 5 (15). The same volume element of theslurry/flocculent mixture S+F is therefore led both past the fronttreatment edges 41 and 43 and past the rear treatment edges 42 and 44and further swirled and intermixed.

However, the second effect mentioned is caused by the pressuredifferences themselves which, even from a certain size, may bring about,in the same way as in a cavitation nozzle, cavitation effects whichimprove the mixing of the mixture S+F even while it flows inside theinterspace 5 (15) between the treatment edges.

Finally, in an embodiment which is not illustrated, it is also possiblethat, in the direction of rotation T, the axial width of the treatmentelements 4 and 14 increases from a minimum width B2 at the front on theflat side 47 to a maximum width B1 at the rear on the flat side 48 andcorrespondingly, in the direction of rotation T, the axial width of theinterspaces 5 and 15 decreases from a maximum width W2 at the front to aminimum width W1 at the rear. In this embodiment, therefore, the inletorifice 51 of the interspaces 5 and 15 is always larger than the outletorifice 52 of the interspaces 5 and 15. In this embodiment, theslurry/flocculent mixture S+F is thus only compressed, not firstdecompressed, on its way through the interspaces between the treatmentelements. In this embodiment, too, good full mixing results areachieved. Particularly in this embodiment, but also in all the others,treatment edges may also be provided at the outlet orifice 52 only,whereas obtuse or curved and/or funnel-shaped inflow regions may also beprovided at the inlet orifice.

The selected ratio B1/B2 of the maximum axial width B1 to the minimumwidth B2 of the treatment elements 4 and 14 is preferably greater than2, preferably between 2 and 3.5. The selected ratio W2/W1 of the maximumaxial width W2 to the minimum width W1 of the interspaces 5 and 15 ispreferably greater than 1.4, preferably between 1.5 and 2.8. Theseratios B1/B2 or W2/W1 are a measure of the relative decrease or increasein the axial width of the treatment elements or in the axial width ofthe interspaces between the treatment elements and therefore alsodetermine the degree of compression (or, if appropriate, decompression)of the slurry/flocculent mixture S+F.

Finally, in a further embodiment which is not illustrated, it is alsopossible not to vary the width of the treatment elements 4 and 14 or thewidth of the interspaces, that is to say to keep them constant in thedirection of rotation T.

In a further embodiment, not illustrated, the interspaces 5 and 15 mayalso be closed off radially outward in order to prevent theslurry/flocculent mixture S+F from being forced out due to thecentrifugal forces. For example, a bar-shaped or rod-shaped longitudinalpart which runs axially to the axis of rotation R and closes all theinterspaces 5 and 15 may be arranged on the outside over the comb-likestructure of each row of treatment elements 4 and 14. This gives rise toa ladder-like structure instead of a comb-like structure. Thelongitudinal part, too, may again have treatment edges, in particularaxially running treatment edges, on the outside and, in particular, bedesigned as a square or square tube which is applied, for example bywelding, from outside to the outer faces of the treatment elements.

Furthermore, in all the embodiments, a reversing function or reversingoperation for the purpose of cleaning the interspaces 5 and 15 may beprovided, in which the rotor is rotated in an opposite direction to thedirection of rotation T provided in mixing operation, above all in orderto remove larger particles from the interspaces.

The treatment edges 41 to 44 are preferably of sharp-edged form in orderto achieve good swirling. In a further embodiment, the surface of thetreatment rotor 1 may be provided, at least at the treatment edges, witha wear protection layer, for example a layer produced by plasmanitriding or a ceramic coating, in particular an aluminum oxide layer,for example by spraying on, or else a hard material layer, for example aTiN or TiCN layer.

The treatment elements 4 and 14 may be connected in one piece to oneanother and/or to the basic body or else be plugged as prefabricatedparts into orifices in the basic body and be introduced into the innerspace and then fastened by means of screws and/or crossbeams.

According to FIGS. 7 and 8, to rotate the treatment rotor 1 in the feedline 9, said rotor is coupled, for example nonpositively, to a motor 10via the coupling element 3. During operation, slurry S is pumped orrouted through the feed line 9 while the treatment rotor 1 is rotated bythe motor 10. At the same time, flocculent is delivered through thetreatment rotor 1. In this case, the treatment rotor 1 is preferablysurrounded completely by slurry S, this being especially advantageous interms of treatment efficiency.

It is advantageous if the cross-sectional area which is occupied by thetreatment rotor 1 and which corresponds, particularly in the exemplaryembodiment illustrated, to the product L5L6 is greater than 50% andsmaller than 74% of the flow cross-sectional area of that feed lineportion of the feed line 9 in which the treatment rotor 1 is arranged.

Sealing elements may also be provided in the region of the couplingelement 3 in order to seal off the coupling element 3 with respect tothe feed line 9 against the passage of slurry S or liquid. A check unitfor the motor 10 and for the feed pump or feed pumps, not illustrated,for the flocculent F and preferably also the slurry S is designated by11. The rotational speed of the treatment rotor 1 may advantageously beselected between 1200 and 4000 rev/min., and the slurry volume flow inthe feed line 9 may typically amount to 3 to 400 m³ per hour.

The apparatus illustrated in FIGS. 7 and 8 may have further treatmentrotors 1 which precede or follow the treatment rotor 1 shown or else areconnected in parallel and which may be incorporated into the feed line 9in a similar way to that described above. The apparatus 7 may,furthermore, be followed in the flow direction or transport direction ofthe slurry S by a mechanical drying device, not shown, in particular afilter press or centrifuge, for drying or dewatering the slurry S, theflocculent F largely remaining in the separated water or liquid.

The apparatus illustrated in FIGS. 7 and 8 may also have furthertreatment rotors 1 which precede or follow the treatment rotor 1 shownor else are connected in parallel and which may be incorporated into thefeed line 9 in a similar way to that described above.

In the disintegration of slurry S, the slurry/flocculent mixture S+Fmust be replaced, as described, by the slurry S, while the operatingmode and design of the treatment rotor 1 may remain essentially thesame. The disintegration action, too, is greatly improved, in a similarway to the mixing in action, by the configuration of the treatment rotoraccording to the invention, in particular the swirling and compressionand decompression effects described. The perforations 6 may serve herefor the passage of slurry S or may even be dispensed with entirely.

LIST OF REFERENCE SYMBOLS

1 Treatment rotor

2 Rotor basic body

3 Coupling element

4 Treatment element

5 Interspace

6 Perforation

7 Treatment element

8 Fastening element

9 Transport or feed line

10 Motor

11 Check unit

14 Treatment element

15 Interspace

17 Treatment element

18 Fastening element

20 Inner space

21 Wall

41 to 44 Treatment edge

45, 46 Side wall

47, 48 Flat side

49 Outer face

50 Boundary wall

51 Inlet orifice

52 Outlet orifice

53 Outlet orifices

R Axis of rotation

T Direction of rotation

B1 First axial width

B2 Second axial width

D Inside diameter

L1 to L8 Dimension

F Flocculent

S Slurry

1. (canceled)
 2. (canceled)
 3. A method for mixing a conditioning agentinto a slurry, the method comprising the steps of: placing a treatmentrotor rotatable about an axis of rotation into the slurry, the treatmentrotor having first and second treatment elements projecting outward fromthe axis of rotation, the first and second treatment elements definingan interspace between the first and second treatment elements;introducing the conditioning agent from the treatment rotor into theslurry; rotating the treatment rotor about the axis of rotation; anddirecting the slurry and the conditioning agent into the interspace viathe rotation of the treatment rotor, wherein the slurry and theconditioning agent are first directed along a first region of theinterspace increasing in width and subsequently directed along a secondregion of the interspace decreasing in width, the width of theinterspace measured in a direction parallel to the axis of rotation, andwherein directing the slurry and the conditioning agent along the firstregion and then the second region intensifies mixing of the conditioningagent into the slurry.
 4. The method of claim 3, further comprisingseparating a liquid from solids in the slurry, including solid fractionsof cells of organic origin contained in the slurry, subsequent to theintroduction of the conditioning agent.
 5. The method of claim 3,further comprising forming flaky structures of differing sizes fromsolids in the slurry subsequent to the introduction of the conditioningagent.
 6. The method of claim 3, further comprising releasing solidcellular constituents of the slurry subsequent to the introduction ofthe conditioning agent.
 7. The method of claim 3, wherein directing theslurry and the conditioning agent into the interspace while thetreatment rotor is rotated comprises directing the slurry and theconditioning agent into the interspace having a ratio of a maximum widthto a minimum width between 1.5 and 2.8.
 8. The method of claim 3,wherein the conditioning agent is introduced from the treatment rotorinto the slurry at a slot defined by a body of the treatment rotor at alocation outside of the interspace.
 9. The method of claim 3, furthercomprising disintegrating the slurry by rotating the treatment rotorabout the axis of rotation prior to introduction of the conditioningagent.
 10. A method for treating a slurry using an apparatus, the methodcomprising the steps of: placing a treatment rotor of the apparatus intothe slurry, wherein the treatment rotor is rotatable about an axis ofrotation, and wherein placing the treatment rotor into the slurrycomprises placing into the slurry first and second treatment elementsprojecting outward from the axis of rotation, the first and secondtreatment elements defining an interspace therebetween; rotating thetreatment rotor about the axis of rotation; decompressing the slurrywithin the interspace via the rotation of the treatment rotor about theaxis of rotation; and compressing the slurry within the interspace viathe rotation of the treatment rotor about the axis of rotation, thecompressing being subsequent to the decompressing.
 11. The method ofclaim 10, further comprising the step of: introducing a conditioningagent into the slurry.
 12. The method of claim 11, wherein theconditioning agent is introduced into the slurry from an axial slotdefined by a body of the treatment rotor on which the first and secondtreatment elements are formed, the axial slot running substantiallyparallel to the axis of rotation along at least a portion of the body.13. The method of claim 12, wherein the axial slot is defined by thebody at a location between first and second rows of treatment elements.14. The method of claim 11, further comprising the step of: separating aliquid from solids in the slurry subsequent to introducing theconditioning agent into the slurry.
 15. The method of claim 10, whereindecompressing the slurry within the interspace occurs along a firstlocation within the interspace where a width of the interspace, measuredin a direction parallel to the axis of rotation, increases in adirection of rotation about the axis of rotation.
 16. The method ofclaim 15, wherein compressing the slurry within the interspace occursalong a second location within the interspace where a width of theinterspace, measured in the direction parallel to the axis of rotation,decreases in the direction of rotation about the axis of rotation. 17.The method of claim 10, wherein the first and second treatment elementsdefine the interspace to be of a convexly curved form.
 18. The method ofclaim 10, wherein placing into the slurry the first and second treatmentelements comprises placing a first row of treatment elements includingthe first and second treatment elements into the slurry and placing asecond row of treatment elements into the slurry, the first and secondrows offset from one another by approximately 180 degrees relative tothe axis of rotation.
 19. The method claim 18, wherein the treatmentelements of each of the first and second rows are aligned along a commonaxis running parallel to the axis of rotation.
 20. The method of claim10, wherein rotating the treatment rotor about the axis of rotationcomprises coupling the treatment rotor to a rotary device via a couplingelement to rotate the treatment rotor about the axis of rotation.